4,472 research outputs found

    CHANTI: a Fast and Efficient Charged Particle Veto Detector for the NA62 Experiment at CERN

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    The design, construction and test of a charged particle detector made of scintillation counters read by Silicon Photomultipliers (SiPM) is described. The detector, which operates in vacuum and is used as a veto counter in the NA62 experiment at CERN, has a single channel time resolution of 1.14 ns, a spatial resolution of ~2.5 mm and an efficiency very close to 1 for penetrating charged particles

    Redox activity of melanin from the ink sac of Sepia officinalis by means of colorimetric oxidative assay

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    The redox properties of natural extract from cuttlefish ink sac (Sepia officinalis) and synthetic melanin used as a biomimetic in melanin structural investigation were determined by comparison of this phenol-based heterogeneous pigment with gallic acid used as a standard in Folinâ Ciocalteu colorimetric assay widely employed for characterisation of oxidative properties of biomaterials. Reactivity of sepia melanin reported here is much higher than previously indicated and this protocol should allow the redox characterisation of all melanins irrespective of their origin and composition.European Union’s Seventh Framework Programme (FP7/2007-2013) [grant agreement number REGPOT-CT2012-316331-POLARIS

    A prototype large-angle photon veto detector for the P326 experiment at CERN

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    The P326 experiment at the CERN SPS has been proposed with the purpose of measuring the branching ratio for the decay K^+ \to \pi^+ \nu \bar{\nu} to within 10%. The photon veto system must provide a rejection factor of 10^8 for \pi^0 decays. We have explored two designs for the large-angle veto detectors, one based on scintillating tiles and the other using scintillating fibers. We have constructed a prototype module based on the fiber solution and evaluated its performance using low-energy electron beams from the Frascati Beam-Test Facility. For comparison, we have also tested a tile prototype constructed for the CKM experiment, as well as lead-glass modules from the OPAL electromagnetic barrel calorimeter. We present results on the linearity, energy resolution, and time resolution obtained with the fiber prototype, and compare the detection efficiency for electrons obtained with all three instruments.Comment: 8 pages, 9 figures, 2 tables. Presented at the 2007 IEEE Nuclear Science Symposium, Honolulu HI, USA, 28 October - 3 November 200

    PEN experiment: a precise measurement of the pi+ -> e+ nu decay branching fraction

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    A new measurement of Bπe2B_{\pi e2}, the π+e+ν(γ)\pi^+ \to e^+\nu(\gamma) decay branching ratio, is currently under way at the Paul Scherrer Institute. The present experimental result on Bπe2B_{\pi e2} constitutes the most accurate test of lepton universality available. The accuracy, however, still lags behind the theoretical precision by over an order of magnitude. Because of the large helicity suppression of the πe2\pi_{e2} decay, its branching ratio is susceptible to significant contributions from new physics, making this decay a particularly suitable subject of study.Comment: 4 pages, 3 figures, talk given at the Tenth Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2009), La Jolla/San Diego, CA, 26-31 May 2009; to appear in Proceedings to be published by the American Institute of Physic

    EuCARD Newsletter Issue 2

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    European Coordination for Accelerator Research and Development (EuCARD) Newsletter Issue 2: July - September 2009 * A word from the Governing Board Chairman * Amassing the neutrino community * Start by probing the crab cavities * Breaking news for Proton "Surfatrons" * For EuCARD members: Interim reportin

    PEN: a low energy test of lepton universality

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    Allowed charged π\pi meson decays are characterized by simple dynamics, few available decay channels, mainly into leptons, and extremely well controlled radiative and loop corrections. In that sense, pion decays represent a veritable triumph of the standard model (SM) of elementary particles and interactions. This relative theoretical simplicity makes charged pion decays a sensitive means for testing the underlying symmetries and the universality of weak fermion couplings, as well as for studying pion structure and chiral dynamics. Even after considerable recent improvements, experimental precision is lagging far behind that of the theoretical description for pion decays. We review the current state of experimental study of the pion electronic decay π+e+νe(γ)\pi^+ \to e^+\nu_e(\gamma), or πe2(γ)\pi_{e2(\gamma)}, where the (γ)(\gamma) indicates inclusion and explicit treatment of radiative decay events. We briefly review the limits on non-SM processes arising from the present level of experimental precision in πe2(γ)\pi_{e2(\gamma)} decays. Focusing on the PEN experiment at the Paul Scherrer Institute (PSI), Switzerland, we examine the prospects for further improvement in the near term.Comment: 11 pages, 5 figures; paper presented at the XIII International Conference on Heavy Quarks and Leptons, 22-27 May 2016, Blacksburg, Virginia, US

    NA62 present status

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    NA62 is a fixed-target experiment located in the CERN experimental North Area. The beam is provided by SPS. During the first phase (2007 → 2010) the collaboration measured the ratio RK = BR(K → eν)/BR(K → μν). This measurement is sensitive to Standard Model (SM) deviations; in particular it can test lepton universality. During the second phase, the collaboration aims to measure BR(K+ → π+ν¯ν). Due to the sensitivity of this BR to new physics, this decay has a strategic role in the search for physics beyond the SM. The hadronic contribution to the uncertainty is small and the SM prediction is precise: (8.5 ± 0.7)10−11. The apparatus is under construction and the first run is expected for spring 2013. The detector status, prototype tests, and signal sensitivity compared with background rejection will be discussed

    CERN West Area neutrino facility beam line alignment

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    This papers describes the alignment of the West Area Neutrino Beam Line at CERN to the two neutrino experiments CHORUS and NOMAD. The T9 neutrino (n) target position and the position of the magnetic horn were optimised using the secondary muon intensity profiles from the muon pits in the shielding. In the experiments the improved geometry provides a better centred beam (< 5 cm) and a measured increase in the n flux of 8%
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